Instead, you need to use a sign that describes what you mean by "good." For example:
* "Good" as in "good job": You would sign "well done" or "nice" by making a thumbs up sign and moving it slightly forward.
* "Good" as in "good morning": You would sign "morning" or "hello".
* "Good" as in "good food": You would sign "delicious" or "tasty".
It depends on the context of the situation and the meaning you want to convey.